Sagot :

3 (a+6) = 3xa + 3x6

5 (a2-3) = 5xa2 + 5x(-3)

-2 (2-3x) = -2x2 + (-2)x(-3)

-6 (2-3x) = -6x2 - 6x-(-3x)

-x (3x-x2) = -xx3x -xx(-x2)